Use the below command to create a self-signed certificate: openssl req -x509 -days 365 -nodes -newkey rsa:2048 -keyout tls.key -out tls.crt \ -subj “/C=CN/ST=Shandong/L=Qingdao/O=Nokia/OU=RD Team/CN=deskshell.com” A very good reference material can be found in digital ocean as below openssl essentials
recommend two npm registries in China
做Web前端开发离不开npm, 开发人员可以使用npm来管理项目的各种依赖包，公开的依赖包都被保存在一个统一的服务器上，它的访问地址为https://registry.npmjs.org。然而在国内访问这个地址时，有时比较慢，下载依赖包的过程中经常卡住。这里推荐两个国内的npm registry。从这两个registry下载package时，速度相对快很多。
delete branches in the remote git repository
There are two methods to delete a branch in the remote git server. Either of these two commands is OK. git push origin :BRANCH_TO_BE_DELETED git push –delete origin BRANCH_TO_BE_DELETED Please note the colon in the first command. In order to… Read More
suppress skipping task names in ansible 2.7 console output
In my post ‘do not display skipping task in ansible‘, I mentioned that the stdout_callback = full_skip configuration can suppress the skipping task names in the ansible console output. However, after I upgrade ansible to 2.7.6, I find that there are duplicated… Read More
nvm ls-remote results in NA
Today I installed the nvm tool in my Linux server. When I run the ‘nvm ls-remote’ command, I got the below weird message: #nvm ls-remote N/A Because the Linux server is behind the company firewall, I have setup the environment… Read More
do not display skipping tasks in ansible
Recently one of our developers complained the skipping tasks displayed in the ansible output. She insisted that the skipping tasks names and the skipping keyword should not be displayed, because these stuffs may confuse customers. I agree with her. Without… Read More
token bucket 算法简析
最近在解决一个Linux下DHCP无法获取IPv6地址的问题。在分析过程中发现，把IPv6防火墙停掉的话，用dhclient就可以给网卡获取到IPv6地址，否则就无法获取。初步判断，是IPv6的防火墙的问题。 在查看/var/log/iptables.log时，发现里面的log很少，几乎没有什么有用的log。在查看ip6tables rules时，发现有如下的一条规则用于控制log的输出： -A LOGGING6 -m limit –limit 2/hour -j LOG –log-prefix “IP6TABLES DROP:”
avoid ignored error message in ansible
In ansbile playbook, the below style can be used to check the result of a script or command, and give a meaningful message if the task fails. – name: check stack existance hosts: localhost any_errors_fatal: True tasks: – name: check… Read More
package selection in rhel6 and rhel7 kickstart
Recently our product is migrating from rhel6 to rhel7. During this process, we encountered a wired issue that some rpm packages couldn’t be installed during Linux installation. We are using a customized rhel iso, which is originally downloaded from redhat… Read More
在RHEL7上搭建kubernetes 1.11集群
在RHEL7的虚拟机上搭建一个kubernetes 1.11集群，环境如下 master: 192.168.10.1 node1: 192.168.10.2 node2: 192.168.10.3